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Following in Real Time the Impact of Pneumococcal Virulence Factors in an Acute Mouse Pneumonia Model Using Bioluminescent Bacteria
11:32

Following in Real Time the Impact of Pneumococcal Virulence Factors in an Acute Mouse Pneumonia Model Using Bioluminescent Bacteria

Published on: February 23, 2014

Structure of deoxyribonucleic acid on the cell surface during uptake by pneumococcus

D A Morrison, W R Guild

    Journal of Bacteriology
    |September 1, 1973
    PubMed

    Insights

    This study reveals that Diplococcus pneumoniae can take up DNA fragments of varying sizes, both native and sheared, which remain active in transformation. DNA entry into the cell is a non-specific process sensitive to ethylenediaminetetraacetate.

    Area of Science:

    • Molecular Biology
    • Genetics
    • Microbiology

    Background:

    • Understanding DNA uptake mechanisms in bacteria is crucial for genetic research.
    • Diplococcus pneumoniae is a key model organism for bacterial transformation studies.

    Purpose of the Study:

    • To investigate the state and activity of donor deoxyribonucleate (DNA) bound to competent Diplococcus pneumoniae cells.
    • To determine the characteristics of DNA fragments that enter the bacterial cell.

    Main Methods:

    • Exposure of competent Diplococcus pneumoniae cells to high-molecular-weight donor DNA.
    • Analysis of DNA sensitivity to deoxyribonuclease I.
    • Elution of DNA using 5 M guanidine hydrochloride.
    • Assessment of DNA transformation activity.

    Main Results:

    • Two fractions of bound DNA were identified: one elutable with guanidine hydrochloride (lower molecular weight, active in transformation) and one resistant (native, active in transformation).
    • Breaks in extracellular DNA do not appear to occur at genetically specific sites.
    • DNA entry into the cell, even at 0 C, is a process sensitive to ethylenediaminetetraacetate.

    Conclusions:

    • Diplococcus pneumoniae can internalize both native and processed DNA fragments.
    • The bacterial cell barrier allows DNA entry through a non-specific, temperature-independent mechanism.
    • These findings contribute to the understanding of bacterial genetic transformation and DNA processing.

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